Using the sun's energy to heat water is one of the oldest ways to generate hot water. It is a widely used technology in sunny climates, but recent technological progress makes it a viable and cost effective solution even for northern European markets. Solar thermal collectors are the most eco-friendly way to heat your domestic water for your shower, bath or your kitchen.

Solar thermal systems have been in operations around the world for decades, and other countries have made solar thermal system compulsory for new buildings (recently Spain joined the list).

There are many manufacturers of solar thermal systems, most of which are from Europe. In broad terms the European manufacturers produce good quality solar panels. It is important to check that the solar thermal panels are tested to European standard EN12975 and certified by a reputable institution.

Despite common belief, the UK receives slightly more than half of the solar energy received at the equator and around 65-70% of the sun that Spain gets. This is enough to operate a solar heating system.

A well designed solar water heating system can provide 50% - 60% of your annual domestic hot water requirements (e.g. shower, bath, and kitchen). This means that in the summer the solar system will provide 90-100% of your hot water needs, and in the winter it will save energy by primarily pre-heating your water and giving the boiler less "work" to do, thus conserving energy, prolonging the life of the boiler and reducing emissions of greenhouse gases.

Quality systems work by absorbing diffused light and converting it into heat. In other words, even on a cloudy winter day the diffused light will preheat the water in the cylinder and provide major savings.

If necessary, your backup systems (e.g. your boiler) will up-heat the water from the already warm temperature to your preferred temperature.

On long summer days, the length of exposure to the diffused light is a major advantage. Even if the sky is overcast, the fact that the days are so long helps heat the water to very good levels.

Typically a installing a solar thermal system lasts approximately 2 days. This, naturally, will vary depending on the type of property, the type of roof etc.

During the installation the engineer takes special care to ensure that there is minimum disruption and the supply of hot water is typically up and running within a few hours, to that the normal household routine is not disturbed.

As explained above, installations vary in price due to different circumstances such as roof complexity, loft access etc. As a general guide, a typical installation for an existing 3-4 bedroom house should cost £3,500-5,000.